| Abstract |
A Gram-reaction-positive, non-motile, non-spore-forming, catalase-negative, facultatively anaerobic, rod-shaped, β-glucosidase-producing lactic acid bacterium, designated strain THK-V8(T), was isolated from the Korean fermented food, Kimchi, and its taxonomic position was investigated by using a polyphasic approach. Strain THK-V8(T) was able to grow at 4-40 °C (optimum, 30 °C) and pH 4.0-7.0 (optimum, pH 6.0). Strain THK-V8(T) had the ability to transform ginsenoside Rb₁ to Rd. On the basis of 16S rRNA gene sequence similarity data, strain THK-V8(T) was shown to belong to the genus Lactobacillus. Strain THK-V8(T) was related to Lactobacillus koreensis DCY50(T) (98.8% sequence similarity), Lactobacillus parabrevis LMG 11984(T) (97.7%), Lactobacillus senmaizukei L13(T) (97.5%), Lactobacillus hammesii TMW1.1236(T) (97.3%) and Lactobacillus brevis ATCC 14687(T) (97.2%). Subsequently, sequence analysis of the RNA polymerase alpha subunit gene (rpoA) confirmed that strain THK-V8(T) showed a maximum rpoA gene sequence similarity value of 93% with Lactobacillus brevis LMG 6906(T). The G+C content of the genomic DNA was 47.8 mol%. The DNA-DNA hybridization values between strain THK-V8(T) and Lactobacillus parabrevis DCY50(T) and Lactobacillus parabrevis LMG 11984(T) were 46.1 ± 4.9% and 10.6 ± 2.9%, respectively. The major fatty acids were summed feature 7 (comprised of C(19:0) cyclo ω10c/19ω6), C(14:0), C(16:0) and C(18:1)ω9c. The cell wall peptidoglycan was of the A4α L-Lys-D-Asp type. The phenotypic and molecular properties indicated that strain THK-V8(T) represents a novel species within the genus Lactobacillus, for which the name Lactobacillus yonginensis sp. nov. is proposed. The type strain is THK-V8(T) ( =KACC 16236(T) =JCM 18023(T)).
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